Expectations were low for this year’s UNFCCC climate negotiations in Doha, Qatar (COP 18), which concluded last week. It was scheduled to be a “finalize-the-rules” type of COP, rather than one focused on large, political deals that went into the early hours of the morning. Key issues on the table included finalizing the rules for the Kyoto Protocol’s second commitment period; concluding a series of decisions on transparency, finance, adaptation, and forests (REDD+); and agreeing on a work plan to negotiate a new legally binding international climate agreement by 2015. The emissions gap was also front-and-center, as the new UNEP Gap Report showed that countries are further away than even a year ago from the goal of keeping global average temperature rise below two degrees C.

If you asked five different people what they think “equity” means, you’d probably get five different answers. Their personal experiences and opinions would be overlaid on their cultural perspectives. A philosopher might bring up Aristotle’s teachings on justice; an economist would likely talk about maximizing utility and efficiency. A Buddhist and a Muslim might frame their answers from different perspectives that are difficult to compare, just as the viewpoints would likely vary between people raised under different forms of government.

So it’s no surprise that when climate negotiators from nearly 200 countries come together at the end of each year, they can’t agree on what exactly ‘equity’ means as applied to addressing climate change. To further complicate matters, the UN Framework Convention on Climate Change (UNFCCC) ties equity to “common but differentiated responsibilities and respective capabilities (CBDR-RC).”

There are many legitimate views of what equity means in the context of the UNFCCC, reflecting sharp contrasts on how to share both the burdens and opportunities of the global transition to low-carbon development. Some countries emphasize “responsibilities,” usually explained as the historical responsibilities developed countries have because of the greenhouse gases they emitted in the process of growing economically. Other countries focus on “capabilities,” the capacity countries have now to deal with climate change, such as their financial and technological resources to reduce domestic emissions or support adaptation research and activities. Several options for “differentiation” have been suggested over the years, including historical responsibility, levels of economic development, and vulnerabilities and needs. The current approach to equity has become a tug-of-war between countries that are reluctant to make greater climate change action commitments without assurances that others will also act.